It has heretofore been proposed to provide one or more gate valves on pumping apparatus as in the main pump-booster pump system of U.S. Pat. No. 2,428,256 to Yates of Sept. 30, 1947.
It is also well known to provide pressure relief valves in fire fighting, or other liquid, systems, the valve usually being located on the hose side of the pumps to protect the hose from fracture.